Radial glial cells (RGCs) are one of the earliest cell types to appear in the developing central nervous system (CNS). RGCs function as neuronal progenitors, as well as a glial scaffold to support neuronal migration into the developing layers of the cerebral cortex. RGCs do not persist into the adult mammalian CNS. Instead, these cells transform into mature astrocytes and ependymal cells in the postnatal period of development.
It was believed that the adult mammalian brain was not capable of regenerating neurons. However, the recent discovery of adult neural stem cells (NSCs) demonstrates that multipotent neural stem cells are present in adult mammalian brains, which can proliferate and differentiate upon appropriate stimuli into all lineages of neural cells, including neurons and glial cells (astrocytes and oligodendrocytes). It therefore appears possible to generate neural cells using neural stem cells in the treatment of diseases or conditions caused by neural cell loss or damage. Nevertheless, proper maturation and migration of neuronal precursors would require radial glial cells, which are lacking in the adult mammalian brain. Consequently, it is desirable to reestablish a radial glial cell population in the adult mammalian brain, which will help to recapitulate developmental processes normally absent in the mature CNS, thereby aiding in the regeneration of damaged or diseased CNS tissue. Given that very little is known about the signals involved in the generation, differentiation, and postnatal transformation of RGCs, the need exists for a method of producing radial glial cells.